Coracle
A one-person boat you carry on your back: a woven frame of split laths, a hide or cloth skin, and pitch, built in about two days.
Home: On water, Level 1 · Foothold, level 1 of 6 in its track. Serves 1 step.
Every build on this site has hazards that injure or kill — quicklime, carbon monoxide, molten metal, collapsing ground. Read the safety notice before starting, and read this build's own failure modes below.
What it is and why this shape
The coracle is the lightest boat there is for its load: a basket frame, a seat and a waterproof skin, carried on the back to the water. It crosses rivers, sets and hauls nets, and ferries one person and a little cargo. Round basket boats of the same idea are still worked every day on the rivers and coasts of India and Vietnam. It is a category D boat for one person: it spins, drifts with wind and current, and has no reserve for a second adult. The pattern here is the Coracle Society's Ironbridge coracle (guide), with the no-nail, hide-covered way of the Teifi makers for a group with no nails or cloth.
Coracle frame, in plan
Fig 1
Timber
Coracle, section across the seat
Fig 2
TimberWaterVoid / air
Keyed parts
| 1 | Seat | 105 × 20 × 2.5 cm across the middle; its length sets the beam. |
| 2 | Gunwale | Laths bent round from the seat ends, or 3 rows of woven rods: the rim everything else is fixed to. |
| 3 | Stringers | 7 laths lengthwise, woven over and under the ribs. |
| 4 | Ribs | 9 laths across: 5 in front of the seat, 3 behind, 1 under it, about 10 cm apart. |
| 5 | Seat posts | 3, 28 cm tall and 23 cm apart along the seat, standing on the frame's bottom. |
| 6 | Skin | Hide or cloth, stretched over the frame, turned over the gunwale and waterproofed. |
Specifications
| Size | 1.40 × 1.07 m, 31 cm deep | The Ironbridge pattern. |
| Frame | 7 stringers, 9 ribs, 4 corner diagonals | Laths 2.5 m × 4 cm × 5 mm, about 10 cm apart. |
| Seat | 105 × 20 × 2.5 cm | On 3 posts 28 cm tall; its length sets the beam. |
| Skin | one hide, or 1.9 × 1.8 m of calico | Hide greased and pitched; calico painted with 3 coats of bitumen. |
| Load | one adult | About 10 cm of draught and 21 cm of side, just FAO's 0.2 × beam; a second adult leaves about 11 cm. |
| Paddle | 1.3 m, blade 40 × 20 cm | Worked over the front in a figure of eight. |
Bill of materials
| Material | Quantity | Notes and substitutes |
|---|---|---|
| Laths | 30 × 2.5 m | Green ash, willow or hazel, split and shaved to 4 cm × 5 mm. Cut in winter, used fresh. |
| Rods for the rim | about 20 | Finger-thick hazel or willow, woven round the gunwale in 3 rows (the Teifi way); or 4 more laths, nailed. |
| Seat | 1, 105 × 20 × 2.5 cm | With 2 supports 20 × 5 × 2.5 cm and 3 posts 28 × 4 × 4 cm. |
| Skin | 1 ox or buffalo hide, or calico 1.9 × 1.8 m | Hide was the first cover; in Wales flannel, then calico, replaced it from about 1800. |
| Waterproofing | about 2 litres | Hide: tallow, then pitch on the seams. Cloth: hot pitch and tar, or bitumen paint in 3 coats. |
| Cord, rawhide, or nails | — | For every crossing that is not held by the weave: lashings, or 25 mm nails clenched inside. |
| Paddle | 1 | A 130 cm shaft with a 40 × 20 cm blade let into a slit and fixed. |
| Carrying strap | 1 | Twisted hazel or cord, worn across the upper chest. |
Tools: Knife · Froe or axe, for splitting laths · Drawknife · Awl and a curved needle · Clamps or cord to hold bends · Hammer, if nails are used
Construction
Cut and prepare the laths
Cut straight ash, willow or hazel in winter, when it is sapless. Split each rod and shave it to 4 cm wide, 5 mm thick and 2.5 m long: you need 30. Use them fresh: green laths bend without breaking, and dry ones crack at the bends. If they must wait, keep them in water.
Build the seat
Fix the two seat supports under the ends of the 105 × 20 cm seat. Taper the rear corners, so the boat comes out egg-shaped. Fix three 28 cm posts under the seat along its centreline: one in the middle and one 23 cm either side.
Bend the gunwale
Stand the seat posts up on a flat floor: the frame is built upside down. Fix a pair of laths to the front half of each seat end and bend them together round the front, 65 cm from the seat's front edge to the bow. Do the same, shorter, round the back. Fix every lath to the next all the way round.
Lay the bottom flat
Lay one rib across the posts and three stringers along them, and fix them to the posts. Bend their ends down to the gunwale and fix them. Brace the bottom flat with scrap laths pegged to the floor, about 40 cm out from the posts at the front and 15 cm at the back: a rounded bottom makes a coracle that rolls.
Weave in the rest
Weave the other stringers (7 in all) and ribs over and under, about 10 cm apart: 5 ribs in front of the seat, 3 behind. Bend each to the gunwale and fix it. Add short diagonal laths at the four corners, outside the others, so no wide panel of skin is left unsupported. Trim everything level with the gunwale.
Fix every crossing
The Teifi way, with no nails: the interwoven laths hold each other, and the rim is three rows of finger-thick rods woven round the gunwale. With nails: drive 25 mm nails from the outside and clench them over inside. Either way, nothing sharp may stand proud where the skin will lie.
Put on the skin
Lay the hide or cloth flat, set the frame on it right way up, and draw the edges up over the gunwale, equal all round. Fix it first beside the seat, then at front and back, then work the four corners, taking up the slack in 2–3 pleats each, and sew the pleats closed. Trim below the gunwale inside. A hide goes on wet and shrinks tight as it dries.
Waterproof it
Cloth: three coats of bitumen paint worked in with a stippling brush, about an hour apart in the warm; or hot pitch and tar, as the Welsh makers used. Hide: grease it well and pitch the seams. Paint the inside of the pleats too. Then fix inner and outer gunwale laths over the skin's edge.
Make the paddle, and learn it in shallow water
Slit one end of a 130 cm shaft 25 cm deep and fix a 40 × 20 cm blade in it. Sit centred on the seat, facing forward, and paddle over the front in a figure of eight, blade always in the water. Wear a buoyancy aid, start where you can stand, and get in and out over the middle.
Tolerances that matter
| Dimension | Target | Why it matters |
|---|---|---|
| Bottom | flat | A rounded bottom rolls; brace it flat while the frame is built. |
| Rib and stringer spacing | about 10 cm | Wider panels let the skin sag and tear. |
| Side above water with its paddler | at least 21 cm | FAO's minimum for an open boat: 0.2 × the 1.07 m beam. |
How this fails
Dry laths crack at the bends. Cut them in winter and use them fresh, or soak them.
A rounded bottom, from a frame not braced flat: the coracle rolls.
Nail points or lath ends standing proud under the skin wear through it.
A second passenger. One adult leaves about 21 cm of side; two leave about 11.
Wind and current. A coracle drifts and spins: sheltered water, near the bank, wind below force 4.
How you know it worked
VerificationThe frame's bottom is flat, nothing sharp touches the skin, the skin is still watertight after an hour afloat, and with its paddler seated the coracle floats level with at least 21 cm of side clear; the paddler wears a buoyancy aid.
Scaling and variants
A longer seat (122 cm) makes a slightly larger coracle (Coracle Society). Round basket boats of woven split bamboo, sealed on the outside, work rivers and coasts in India and Vietnam, some big enough for more than one person. Skin boats on a frame — the kayak for one, the umiak for a family — are the same idea drawn long and narrow; Adney and Chapelle describe how they were built.